This type of cleaning tool consists of a generally hollow canister within which is rotated a ball bearing supported tubular drive shaft. At the bottom of the drive shaft is a canister plug connected to a paint applicator holding device which can retain both a paint brush handle and a paint roller cover; either at one time. The top of the canister has a cap with a hole. A drive rod extends through the cap and into the tubular drive shaft contained within the canister. The drive rod has a generally spiral configuration and on the end nearest a handle is located a clutch disk. The clutch disk is mounted above the top of the tubular drive shaft and below the canister cap. The clutch disk, incorporating a bow-tie shaped hole, is rotated by the spiral drive rod. The clutch disk has a plurality of radially extending pawls. The top of the tubular drive shaft connects to a ratchet wheel having a corresponding plurality of upwardly extending triangularly shaped lugs. A cross member is incorporated on the bottom end portion of the drive rod to retain the drive rod within the canister.
As the drive rod is pushed into the canister (downstroke), the spiral drive rod rotates the clutch disk. As the clutch disk rotates, the pawls contact vertical faces of the triangularly shaped lugs on the ratchet wheel. This forces the ratchet wheel, the tubular drive shaft, the canister plug and the paint applicator holding device to rotate, thereby separating, by centrifugal force, retained paint from a paint brush or roller cover mounted thereon.
The upstroke of the drive rod rotates the clutch disk in the direction opposite its rotation during the downstroke. However, on the upstroke, the clutch disk pawls now contact sloped faces on the triangularly shaped lugs, sliding up and over the lugs without forcing counter rotation of the ratchet wheel. Thus, the spinning direction of the paint applicator holding device is always the same.
The upstroke of the drive rod is limited by a cross member at the bottom end portion of the drive rod which cannot pass through the bow-tie hole in the clutch disk.
Prior to the manufacture of paint brush and roller cleaners incorporating the blank clutch disk taught in Hoeltke et. al. U.S. Pat. No. 5,588,221, the likely first failure mode of such devices was complete separation of the drive rod and handle from the rest of the unit. This occurred, unfortunately, on the fly, i.e., while the user was pumping the handle to spin the attached paint brush or roller cover being cleaned. This created a hazardous situation in which the user, unable to instantaneously stop the cyclic thrusting of the now separated drive rod and handle, could impinge the hand holding the canister of the cleaning tool. Indeed, several injuries had been reported.
The cause of these failures was enlargement of the bow-tie hole in the unhardened steel clutch disk, due to excessive wear. This allowed the cross member at the bottom end of the spiral drive rod to escape. Various attempts were made to enhance the durability of the cleaning tool to prevent the separation of the drive rod from the canister.
Tests of cleaning tools incorporating hardened steel clutch disks, unfortunately, resulted in excessive wear of the spiral portion of the drive rods and premature failure of the devices. Hardening of both the clutch disk and the spiral portion of the drive rod resulted in galling, causing the mechanism to jam. Hoeltke's and Fischer's (U.S. Pat. No. 5,588,221) addition of a blank clutch disk, i.e. one not having pawls to engage the lugs on the ratchet wheel that drives the drive shaft assembly, when mounted in tandem with the driving clutch disk, provides a potential solution. The reason why the hole in the blank clutch disk suffers negligible wear throughout the normal life of the drive shaft assembly is because it is not being rotationally loaded as is the driving clutch disk, the former merely spinning idly when the cleaning tool is being used. The driving clutch disk, meanwhile, will suffer the same amount of wear as its predecessors sustained before the addition of the blank clutch disk, but the first failure mode will now be merely the loss of spinnability.
Still, the addition of the blank clutch disk does have drawbacks. Firstly, it could be inadvertently omitted during the assembly process, an occurrence that would go undetected until the drive rod actually separates from the canister, resulting, possibly, in injury to the user. Secondly there is the added material and production costs of the blank clutch disk to the cleaning tool. This includes the additional cost of storage and staging of the blank disk prior to assembly, as well as the labor cost of its assembly. Further, the blank clutch disk does not extend the life of the cleaning tool beyond its previous potential. In other words, the cleaning tool does not last any longer, costs more in raw materials, has increased assembly costs and complexity, and causes more storage costs from increased inventory of parts.
All of the above issues are addressed by the instant invention. The unique combination of a hardened clutch disk and a chrome plated spiral drive rod solves the problem of premature wear out of the bow tie hole in the clutch disk through which the drive rod passes and/or premature wear out of the rod. Galling is virtually eliminated. The useful life of the tool, in fact, is greatly enhanced compared to prior art. Further, the extra part required by Hoeltke et. al. (U.S. Pat. No. 5,588,221) in their solution, including its added assembly cost, is avoided, and the hardened clutch disk cannot be inadvertently omitted from the assembly without being immediately apparent. As simple as this invention seems, it was not apparent to those skilled in the art during the many years after the first spiral drive rod separations were reported up to the present day.